Finding the Fourth Proportional to 2,164.99, 2,987.31 and 1,280.47

Step by Step Solution

1. Step 1: Write the proportion equation
   2,164.99 : 2,987.31 = 1,280.47 : x
2. Step 2: Convert to fraction form
   2,164.99/2,987.31 = 1,280.47/x
3. Step 3: Cross multiply
   2,164.99x = 2,987.31 × 1,280.47
4. Step 4: Simplify right side
   2,164.99x = 3,825,168.30
5. Step 5: Solve for x
   x = 3,825,168.30/2,164.99
6. Step 6: Final answer
   x = 1,766.83